Vehicle power transmission



Jan. 21, 1941. c. E. WESS ELHOFF 2,229,319

VEHICLE POWER TRANSMISSION Filed May 24, 1939 2 Sheets-Sheet l 11vVENTOR direzzz zwxyafi 'A WM, W Vifi mwz A TTORNE ys.

Jan. 21, 1941.

j c. E. WESSELHOFF VEHICLE POWER TRANSMISSION Filed May 24, 1939 2Sheets-Sheet 2 A TTORNE Y5.

Patented Jan. 21, 1941 UNITED STATES VEHICLE POWER TRANSMISSION ClarenceE. Wesselliofi, Detroit, Micln, assignor to Chrysler Corporation,Highland Park, corporation of Delaware Micln, a

Application May 24, 1939, Serial No. 275,388

4 Claims.

This invention relates to motor vehicles and particularly toimprovements in the power transmitting mechanism thereof.

In motor vehicle power transmissions of the type embodying a fluidcoupling for transmitting the drive from the engine to the change speedtransmission it is usually necessary to provide means for disconnectingthe drive when shifting gear ratios to prevent clashing. Thisdisconnecting means is preferably located in the drive between the fluidcoupling runner and the input shaft of the change speed transmission.

Numerous power transmission systems of the aforesaid type have beenproposed and some have gone into use, but difficulty has beenexperienced in providing desired relationship of parts from standpointsof adequate bearing supports, freedom from binding of parts, andarranging the parts so that they do not require more room than isavailable.

Accordingly it is an object of the present invention to provide animproved system of power transmission of the type embodying a fluidcoupling and a clutch which is more economical to manufacture, is morecompact, employs'a lesser number of parts, and is more efficient thanany known in the art. t

A further object of the invention is to provide. an improved frictionclutch which is more compact, less costly to manufacture, require alesser number of parts and is more eflicient than those known in theart.

Further objects and advantages of the invention will be apparent as thisdescription progresses.

Referring to the accompanying drawings in which like reference numeralsdesignate corresponding parts referred to in the following description:'

Fig. 1 is a longitudinal sectional elevational view of the fluidcoupling and clutch assembly. Fig. 2 is a sectional view along line 2-2of Fig. 1.

Fig. 3 is a sectional elevational view of the diaphragm spring used inthe clutch of Figs. 1 and 2.

Fig. 4 is a longitudinalsectional view of a modified form of theinvention.

Fig. 5 is a. sectional view along line 5-5 of Fig. 4.

Fig. 6 is a longitudinal sectional view of a further modification, and

Fig. 7 is a sectional view along line l'| of Fig. 6.

Referring to Figs. 1 and 2, l0 designates the rear end of the enginecrankshaft which is the drive shaft for the power transmission unitabout to be described. The drive of the crankshaft ID is adapted to betransmitted through a fluid coupling A and clutch B to the change speedtransmission C which has an input shaft II.

The fluid coupling A is of the well known kinetictype, but other typesof fluid couplings, such as the reaction turbine type or other types,may be employed.

The change speed transmission 0 may be of the well known manual controltype or it may be sion C may be dispensed with and the shaft ll may bearranged to drive the vehicle ground wheels (not shown) directly withoutpassing through any ratio changing mechanism.

Secured to the rear end of crankshaft H] by the fasteners I2, I haveprovided a supporting journalling member I3 on which is drivinglymounted the impeller structure .14 of fluid coupling A, this impellerhaving the usual radially extending vanes I5 for directing the fluidmedium by the action of centrifugal force toward corresponding vanes itof the runner structure I! whereby to transmit the drive f1'0m theimpeller to the runner in the well known manner.

.'of the automatic type. If desired, the transmis- The impeller l4extends rearwardly and inwardly through the shrouding or cover portionl8 thereby enclosing the runner l1 and in order to seal the fluidcoupling against escape of the fluid I have provided the sealingstructure l9 between the shrouding l8 and the hollow hub 20 on which therunner I1 is drivingly mounted, it being understood that the runner isadapted to rotate relative to the impeller and its shrouding l8. Thesealing structure l9 rotates with the shrouding 18 and is-provided witha sealing ring 2| which rotatably engages a companion sealing member 22carried by the hollow hub 20 in order to accommodate this relativerotation between the impeller and runner while preventing the escape offluid from the coupling A.

The support member l3 has a portion 23 thereof which extends rearwardlywithin the fluid coupling and carries an anti-friction bearing 24providing a journal support for the forwardly extending end of thehub.2ll which extends forwardly withinthe portion 23 of the supportingmember l3. The forward end of hub 20 is closed by a plug 25 forpreventing escape of the fluid from the coupling at this point. Locatedpreferably concentrically within the bearing 24, a

bushing 28 journals the forward end of the input shaft II, the rear endof this shaft being supported by a bearing 21 carried by the housing ofthe transmission C. The rear end of shaft ll may'have the usual inputgear 28 for transmitting the drive to the transmission C.

The hollow hub 20 extends rearwardly preferably with clearance withrespect to the shrouding IS, the rear end of the hub being journaled bya bearing 29 of the anti-friction roll type. Fixed to the rear endportion of the hollow hub so as to surround the bearing 29 is thedriving member 30 of the friction clutch B.

The clutch driven disc 32 is can'ied by a hub 34 drivingly secured tothe input shaft adjacent the rear end of hollow hub 20. A plurality ofcoil springs 33 disposed in juxtapositioned pockets of the members 30and 3| urge the pressure. plate 3| to disengaged position;

An annular cover member 35 is fastened to the pressure plate 30 at aplurality of points by bolts 36. This cover member has a reverselyturned flange portion 35' and is provided with a plurality of slots inwhich the driving lugs 38 of the pressure plate are received.

A diaphragm spring 31 loosely surrounds the shaft II as shown in Figs. 1and 2 and forms the pressure spring for keeping the clutch engaged aswell as a means for controlling the engagement and disengagementthereof. Fig. 3 is an axial longitudinal sectional view of the springwhich has the shape of a dished washer and is provided with a series ofslots 39 between which are the integrally formed fingers 40.

Fig. 1 shows the clutch B in engaged or driving position with the spring31 exerting a forward thrust on the raised ridge 4| of the pressureplate 3|. The reaction of the spring is taken through the outer marginalportion thereof which contacts the inturned edge of the flange 35 of thecover 35. The parts are adjusted during assembly so that full drivingpressure will be exerted on the pressure plate 3| when the spring 31 isfree as illustrated in Fig. l. It .can thus be seen that'drive from thehub 20 will be transmitted to the shaft through the members 30 and 3|which are drivingly connected by the lugs 38 and the driven disc 32which is riveted to the hub 34, the latter being splined on the shaftThe mechanism for disengaging clutch B comprises a hub member 4|slidably carried by the sleeve portion of member 44 which surrounds theshaft II and is fixed to the forward inner wall of the transmissioncasing. The hub 4| carries a throw-out bearing 42 of the usual ball typeand is adapted to receive the fingers of a fork 43, the latter beingadapted to be manipulated ward the right of Fig. 1, whence the bearing42 will be forced against the inner flange 45 of the 1 diaphragm spring31 causing the spring to pivot on the annular flange 35' of cover member35 and through dia hragm action release the pressure from the ridge 4|of pressure plate 3| thus permitting the clutch release springs 33 tomove the ressure plate 3| out of driving contact with the disc 32.Release of the fork 43 allows the hub 4| to be moved forwardly by theusual pedal return spring (not shown) and moves the throwout bearing 42out of contact with the inner ends of the fingers 40. Because of theinherent spring or tension the memb r 31 then pivots about the portion35' of 'cover 35 and exerts pressure on the pressure plate at M,

In the operation of the mechanism, the crankshaft I0 and the impellerstructure |4 rotate in unison causing the fluid in the coupling A torotate the runner IT thereby drivingthev hollow hub 20 and the drivingmember 30 of clutch B. When this clutch is engaged, as illustrated, thedrive passes through the driven disc 32 to the input shaft II and thencethrough the mechanism C to drive the vehicle. The fluid coupling A willordinarily provide sumcient inherent slip at low speeds so that when theengine is idling the clutch B may be left engaged and the mechanism C indriving condition without any drive it is desired to interruptthe drivefrom the crankshaft III to the driving wheels of the vehicle the drivermay bring this about by disengaging the clutch B by operation of thethrow-out mechanism 43.

The fluid coupling A is preferably employed in the system by reason ofits slipping characteristics which cushion and dampen the drive throughthe power transmission system as a whole and also because of thedesirable operating characteristicspf the fluid coupling which, ingeneral, are well known in affording desirable acceleratingcharacteristics of the motor vehicle as well as providing additionaladvantages. While the forward end of the hollow hub 20 may, ifpreferred, be rotatably supported directly by the crankshaft I0, Ipreferably support this hub by the crankshaft through the medium of thesupport member l3.

' By reason of my novel arrangement of parts including the variousbearings, the parts of the power transmission illustrated in Fig. 2 haveimproved stability without tendency toward objectionable vibration andmisalignment of the parts. The input shaft H, for example, isadvantageously, arranged in that it extends between the transmission 0and crankshaft Ill being journalled at the latter location by theconcentrically arranged bearings 26 and 24 through the medium of. theforward portion of the hollow hub 20 which, in turn, is given improvedstability by reason of the widely spaced bearings 26 and 29 on the inputshaft Figs. 4 and 5 illustrate a slightly modified form of the clutch B.Parts corresponding to similar parts in the form previously describedare designated by the same reference numerals with the sufllx a appendedthereto.

In Flgs.'4 and 5, the cover member 350. is connected to the drive member30a by bolts 36a and to the pressure plate 3|a through the inter-.mediarv-of a diaphragm drive member 49. The latter is of dished annularshape and is made from thin stock as indicated in Fig. 5. The member 49is provided with two sets of driving l s. one set designated 5| beingreceived in the spaced slots 50 cut in radially inwardly depressedportions of the cover 350. The other set of lugs designated 52 arereceived in spacedslots 52' cut in the ridge portion 4|a. of thepressure plate. A snap washer 53 is provided to retain the member 49 inposition and prevent rattle. The member 49 is assembled in the structureby inserting it and the pressure plate 4| in assembled relation-into thecover 35 with the lugs 5| in contact with the portion-41 of the coverplate that is intermediate the slots 50. The member 49 is then rotateduntil the lugs 5| are adjacent the slots 50 and moved forwardly. Thediaphragm spring 3111 is thensprung into place between the ridge 4|a ofthe pressure plate and the portions 41 of the cover. The latter issimilar to that of Fig. 1 except that it is flat as 49. The clutchdriven disc 32a is drivingly connected to the hub 34a through aplurality of coil cushioning springs 54 instead of rivets as in theaforesaid form of the invention. These springs may be omitted if desiredand rivets or other rigid fastening means substituted when a fluidcoupling is used in conjunction with the clutch, because the latter willinherently provide suflicient resilience to prevent shock uponengagement of the clutch B.

In Fig. 4 the clutch is shown in engaged position and the driving member49 is flat. When disengaged, the lugs 52 of member 49 are bowedrearwardly. In other words, member 49 acts as a retracting spring aswell as a drive transmitting member.

The clutch release mechanism generally designated by numeral 59 issimilar to that of Fig. 1. Upon rearward movement of the releasemechanism, the bearing 42a contacts the fingers 40a of the diaphragm 31athereby releasing the pressure plate 3m and permitting the member 49 todisengage plate 3|a from driven disc am. A coil spring 58. is providedto maintain the release mechanism in the Fig. 4 position during normaloperation and to prevent rattle.

Figs. 6 and 7 illustrate a further modification in which the diaphragmspring 316 forms the driving connection between the cover 35b and thepressure plate 3lb as well as providing spring pressure for drivingengagement of the clutch. As is apparent from Figs. 6 and 7, the slots39b of the diaphragm 31b terminate in enlarged holes 60 which areadapted to receive the lugs 6| formed on the pressure plate 3"), and aplurality of lugs 63 formed integrally on the member 31b are received incomplementary slots cut in the cover 35b.

The drive. from the engine is thus transmitted from the member 30b tothe pressure plate lib through the cover 55b and the diaphragm 91b, thelatter also supplying the necessary drivingpressure, on pressure plate3lb.

A plurality oi springs 52 mounted in the lugs 6| at three or more pointsin rear of the diaphragm member 31b protrude through the correspondingslots 01' the latter and are hooked around the lugs near the rear faceof the pressure plate as shown in Fig. 6. The springs 62- serve asretaining pins for disengaging the pressure plate 31b from the drivendisc 92b. upon rearward movement of the fork 54, and prevent rattle oithe parts.

Whilethe various forms of the invention havebeen described herein forusewith a fluid coupling, it is desired to point out that my novelclutch is equally useful in motor vehicle or other drives where no fluidcoupling is used and it is not'intended to limit the invention in itsbroader aspects to drives including a fluid coupling as an elementthereoi'. Because of its low cost, compactness and small number ofparts, my improved clutch is particularly applicable for use in alltypes of installations where frequent interruption of drive between aprime mover and a driven mechanism is necessary.

Furthermore, it is not desired, nor is it intended, to limit theinvention to any particular combination or arrangements of parts such asshown and described for illustrative purposes since variousmodifications will be apparent from the teachings of the invention andthe scope thereof as defined in the appended claims.

I claim: I p

1. In a clutch, a driving member; an axially extending cover membercarried by said driving member; a pressure plate drivingly connected tosaid driving member and reciprocable axially relative thereto; a drivendisc disposed between said driving member and said pressure plate; aflexible diaphragm member having an outer marginal portion engaging saidcover member, and an inner portion engaging said pressure plate andnormally urging the same away from said driving member,and means foryieldably maintaining said pressure plate in driving contact with saiddisc.

2. In a clutch, a driving member; an axially extending cover membercarried by said driving member; a pressure plate reciprocable axially ofsaid driving member; a driven disc disposed between said driving memberand said pressure plate; means drivingly connecting said cover memberand said pressure plate comprising an annular flexible diaphragm memberhaving driving lugs in engagement with said cover member and saidpressure plate respectively, said diaphragm member yieldably urging saidpressure plate away from said driving member; and a second diaphragmmember acting between said cover member and pressure plate and yieldablyurging said plate toward said driving member.

3. In a clutch, a driving member; an axially extending cover membercarried by said driving member; a pressure plate reciprocable axially ofsaid driving. member; a driven disc disposed between said driving memberand said pressure plate; means drivingly connecting said cover memberand said pressure plate comprising an annular flexible diaphragm memberhaving driving lugs in engagement with said cover member and saidpressure. plate respectively,.'said diaphragm member yieldably urgingsaid pressure plate away from said driving member and means for normallyyieldably maintaining said pressure plate in driving contact with saiddriving disc.

4. In a clutch, a driving member; an axially extending cover membercarried by said driving member; a pressure plate reciprocable axially ofsaid driving member; a driven disc disposed between said driving memberand said pressure plate; means drivingly connecting. said cover memberand said pressure plate comprising an annular flexible diaphragm memberhaving driv-' ing lugs in engagement with said cover member and saidpressure plate respectively, said diaphragm member yieldably urging saidpressure plate away from said driving member; and a second diaphragmmember acting between said cover member and pressure plate and yieldablyurging said plate toward said driving member, and means operablyassociated with said second tsllilaphrfagm member for releasing thepressure ereo a eminence E. WESSELHOFF.

